Flotation machine



Jan. 2 1, 1936.

` R. P. AKINS FLoTATIoN MACHINE Filed NOV. '7, 1955 2 Sheets-Sheet, 2

Patented Jan. 21, 1936 PATENT OFFICE;

FLOTATION MACHINE Randall P. Akins, Denver, Colo.

Application November 7 Claims.

This invention relates to a otation machine for the concentration ofores and has for its principal object the provision of a machine of thischaracter in which the risingcolumn of air will efficiently act as theagitating medium forthe pulp and provide a circulating current whichwill effectively bring the air into intimate contact with all of the oreparticles. f

Another object is to so construct the tank that the rising column ofbubbles will be continuously forced toward the froth overflow to rapidlyand continuously clear the froth from the machine.

A further object is to provide an air dispersion medium of a type whichwill prevent water from entering the air boxes, either while operatingor during shut downs, and which will be so constructed as to assist inthe propulsion of the gangue toward the discharge of the machine.

Other objects and advantages reside in the detail construction of theinvention, which is designed for simplicity, economy, and eiciency.These will become more apparent from the following description.

In the following detailed description of the invention reference is hadto the accompanying drawings which forms a part hereof. Like numeralsreferto like parts in all views of the drawings and throughout thedescription.

In the drawings:

Fig. 1 isa cross section through the improved flotation machine, takenonthe line I-I, Fig. 5.

Fig. 2 is a detail face view of the upper baille board.

'Fig 3 is a detail face view of the moveable baffle board.

Fig. 4 is a face view of the impeller.

Fig. 5 is a longitudinal section, taken on the line 5-5, Fig. 1.

Fig. 6 is a detail plan view of the air dispersion plate.

Fig. 7 is a cross section through the dispersion plate taken on the line1-1, Fig. 5.

The invention comprises a relatively long spitz-kasten or tank I0. Thebottom of the tank is formed with a. long, relatively narrow,rectangular section, or channel as shown at Above the channel I I, thefront wall I2 of the tank flares outwardly at an angle of approximately45 terminating in a froth overflow lip I3, in front of which the usualfroth launder I4 is positioned. The back wall of the tank also flaresoutwardly, preferably at a steeper angle as shown at |5,`-"thenceextends upwardly as shown et I6; and thence inwardly as shown at to a 7,1933, Serial No. 696,929

horizontal top board or hood I8, `which extends over and above thechannel |I.

'I'he upper area of the tank I0 is divided laterally into a series ofcells by means of lateral partitions I9 which terminate a considerabledistance above the channel Below each of the lateral partitions ISis anair partition 20 which divides the channel into a series of air chambers2|. The top of each air chamber 2| is covered by means of a perforatedplate 22.

It is desiredV to call special attention to the fact that the plates 22are arranged in successive steps, that is, each plate is lower than thepreceding plate, as the discharge extremity of the tank ID isapproached. A feed box 23 is positioned at the head end of the tank andopens thereto through a feed opening 24. A tailings discharge pipe 25opens from the rear end of the tank at a lower level than the lowermostplate 22. Air is fed to the air chambers 2| from an air header 26 whichcommunicates with each air chamber through an independent air pipe 2'I,each of which is controlled by a valve 28. A froth board 4| is spacedfrom the end wall of the tank Ill immediately above the last airpartition 29. The latter is also spaced from the end wall to form asettling chamber 4l for the tailings outlet. Drain nipples 48 extendthrough the bottom of each air chamber 2|, and are closed by means ofsuitable plugs 49.

In each cell an upper baffle board'29 is placed. The upper bale boardsextend downwardly from the hood I8 substantially to or slightly belowthe pulp level. The baffle boards 29 are perforated as shown in Fig. 2,preferably with a series of Vround perforations 30, and a second seriesof elongated perforations 3|. Immediately below the baffle board 29 is amoveable `baille board 32 which rests at its Jextremities in socketmembers 33 positioned against the partitions I9. A third, inclinedbaiile board 34 is placed between the board 32 and the rear tank wallI6, the board being inclined toward the back at its top.

In use, the tailings discharge pipe 25 is turned upwardly at theextremity of the tank a suflicient distance to maintain the solutionlevel therein at the desired point, preferably just below the froth lipI3, as indicated in Fig. 1. 'Air is supplied under the proper pressureto the air chambers 2| and issues through the dispersion plates 22 intothe solution, arising therein in the form of bubbles. The pulp is fedinto the feed box 23 and flows into the first cell and from there, intothe succeeding cells below the partitions |9. The remaining pulp andgangue discharges into the tailings chamber 4|, thence into the tailingsdischarge pipe 25 where it rises and overows the top thereof.

The air arising through the screens 22 passes through the pulp,collecting the metallic values therefrom and elevating them in a risingcolumn of bubbles. This rising column creates an upward current in thesolution which strikes the inclined baille boards 32 and 34, and isdirected by these boards rearwardly and upwardly against the forwardlyinclined back |1. The forwardly inclined back |1 directs the frothforwardly conf stantly urged by the rising column of bubbles at the rearof the tank. This forwardly' moving froth passes through theperforations 30 and 3| in the baille board 29 and onward to the frothoverflow I3. A froth scraper 35 may be provided at this point to assistin passing the froth over into the launder I4, although the machine hasbeen found to operate very satisfactorily without a scraper.

Naturally a quantity of pulp, gangue and solution will becarn'edupwardly with the rising col umn of bubbles. This material willbe deflected by the bale board 29 so that it will descend along theforward. face of the baille 32, which will prevent it from interferingwith. the rising column vof bubbles. The inclined front board I2 willreturn this descending material over the dispersion plates 22 fromwhence it will again be carried upwardly adjacent the rear wall of thetank. 'Ihus all particles of the pulp will be subjected to and travelwith the rising column of air bubbles several times during their passagethrough each cell.

-Tliis whirling action imparts a spiral line of travel throughout thelength of the tank I to all of the solid particles therein. As theyreach the partition I9 of each cell they are carried beneath thepartition and will rise in the next cell. The coarse, heavy,non-floatable material will be carried along each dispersion plate 22 bythe spiral current and will fall to the next succeeding plate throughoutthe length of the machine.

It is desired to call particular attention to the movable baille 32.This baiie is provided with a series of perforations 42 along its upperedge so as to allow the surface current and bubbles to pass. It can beswung to any desired position so as to regulate the rate of circulationin the cell to a point of maximum recovery for the particular ore beingtreated.

It is desired to call particular attention to the dispersion medium orplate 22 which is shown in detail in Figs. 6 and 7. vThis consists of arelatively thin plate of non-corrosive material lthrough which a seriesof narrow, staggered, slots are pierced in such a way as to raise thematerial about each slot on the upper surface of the plate giving it acorrugated effect. This causes the slots to have a wider opening at thebottom than at the top which prevents them from packing ory lling withmaterial. It has been found that a plate of this construction willautomatically seal itself should the supply of air be v cut olf so thatthe pulp will not leak through and enter the air chambers 2|. Thissealing effect is accomplished by the lines or slimes settling over theentire surface of the plate automatically.

The machine as thus far described will operate eiclently andsatisfactorily with a high recovery of values on the usual feed. Itmight be desirable however in some installations to provide a mechanicalimpeller in the rst cell immediately in front of and below the feedopening 24 to act as an emulsier or conditioner or spumer for theentering pulp.

Such a device is illustrated in cell of Fig. 4 and preferably comprisesa vertical shaft 36 suspended in vertical bearings .31 and terminatingimmediately above the dispersion plate 22. This shaft may be rotatedfrom a suitable motor 38 through a belt drive 39. On the bottom of theshaft 36, is an upwardly forcing impeller 40. Spaced a short distanceabove the impeller 40 is a downwardly forcing impeller 4|. The incomingpulp from the opening 24 falls upon the impeller 4| and is forceddownwardly against a rising column of solution and air from the impeller40. These two impacting columns contact and are forced violently outwardin a sheet from between the two impellers,. creating an eiectiveemulsication of the pulp which greatly increases the effectiveness ofthe action of the remaining cells.

The impellers 40 and 4| are preferably formed with an annular, conical,outer band 44 supported upon the extremities of a series of inclinedvanes 43 as shown in detail in Fig. 4. The construction causes thesolution to spread as it leaves the impeller and creates maximumagitation.

If desired a lever 50 (see Fig. 1) may be mounted over each cell andconnected by means of a connecting rod. 5| with the moveable baffle 32.The lever may be held in any desired position by means of a suitabletoothed sector 52. This allows ready and convenient adjustment of theangularity of the baffle 32.

It will be noted that the tailings discharge pipe 25 exits from the tankbelow the top of the lowermost perforated plate 22. This effectivelyprevents sand from building up on the bottom of the tank over theorificesin the perforated plates. It also allows the entire solution andpulp content to be drained from the tank and, as it drains, it will flowwith 'cascading effect from one perforated plate to the next so as towash the plates clean.

'I'he slotted openings 3| in the baille 29 allow wood chips and otherdebris to pass through the bafile and over the froth lip. The pulsatingeffect of the solution eventually aligns all chips with one or more ofthese slotted openings. It will be noted that the hooded top I8, incombination with the froth baille I9, forms an air chamber above thepulp. The rising air creates a compression in this chamber which causesthe compressed air to blow through the perforations 30 and 3| and, in sodoing, it blows the froth toward the discharge.

The lateral partitions I9 prevent intermingling of the rising mineral ofone cell with the rising mineral in the adjacent cells and therebyallows the machine to be used to obtain a classifying effect by properadjustment of the air valves 28. In use, it has been found thatpractically all of the lead in an ore may be floated in the first cell;the copper in the next cells; and the martensite iron in the last cells,dropping the sulphide iron to the tailings discharge, thus obtainingclean classification as well as a concentrate.

It is desired to call attention to the fact that it is not necessary tolift the h`eavy sand particles A feo been described and illustratedherein, it is desired to be understood that the same may be varied,within the scope of the appended claims, without departing from thespirit of the invention.

Having thus described the invention, what is claimed and desired securedby Letters Patent 1. A flotation machine comprising: a relatively longtank; a longitudinal air channel in the bottom of said tank; a series ofair partitions dividing said air channel into a series of air chambers;a perforated member covering'each of said chambers; a forwardly inclinedfront wall in said tank above said channel terminating below thesolution line in said tank; a rear w'all in said tank formed to extendin a general forward direction, said rear wall terminating above thesolution line in said tank; and a baffle board positioned above saidperforated medium and below the. solution level in said ttank, saidbaille board being inclined so as to direct rising material toward saidrear wall, said baille board being hingedly supported so that itsangular position may be varied at will.

2. A notation machine comprising: a relatively long tank; a longitudinalair channel in the bottom of said tank; a series of air partitionsdividing said air channel into a series of air chambers; a perforatedmember covering each of said chambers; a forwardly inclined front wallin said tank above said channel terminating below the solution'line insaid tank; a rear wall in said tank formed to extend in a generalforward direction, said rear wall terminating above the solution line insaid tank; and a bailie board positioned above said perforated mediumand below the solution level in said tank, said baille board being'inclined so as to direct rising material toward said rear wall, theupper edge of said baille board being perforated.

3. A notation machine comprising: a relatively long tank; a longitudinalair channel in the bottom of said tank; a series of air partitionsdividing said air channel into a series of air chambers; a perforatedmember covering each of said chambers; a forwardly inclined front wallin said tank above said channel terminating below the solution line insaid tank; a rear wall in said tank formed to extend in a generalforward direction, said rear wall terminating above the solution line insaid tank; a downwardly extending perforated bailie board extending fromthe forward extremity of said rear wall downwardly adjacent the solution-line in said tank; and a second baille board positioned below thesolution level in said tank, said second baille board being movablymounted so that it may be brought' below said rst baille board whendesired.

4. A notation machine comprising: a tank; an air chamber formed in thebottom of said tank; a perforated medium over said air chamber; meansfor supplying air to said air chamber;

a vertical shaft extending downwardly in said tank; and terminatingabove said perforated me?- dium; a first impeller positioned on thelower 5 extremity of said shaft and arranged to project solutionupwardly from said perforated medium; a second impeller secured to saidshaft above said first impeller and arranged yto project solutiondownwardly toward said first impeller; and means for'rotating saidshaft.

5. A iiotationmachine comprising: a relatively long, narrow, box-likechannel having an open top; a perforated plate closing the top of saidchannel; a front wall extending upwardly and forwardly from one side ofsaid channel; a rear wall extending upwardly the other side of saidchannel, thence forwardly over said channel, so that both said frontwall and said rear wall terminate above and on the same side of saidchannel, said lwalls enclosing a tank, said front wall terminating atthe solution level and said rear Wall terminating above the solutionlevel in said tank; a perforated froth baille extending downwardly fromthe forward extremity of said rear wall substantially to the solutionlevel of said tank; and a baille board positioned below and extendingdownwardly from said first baille over and spaced from said inclinedfront wall.

6. A flotation machine comprising: a relatively-long, narrow, box-likechannel having an open top; a perforated plate closing the top of saidchannel; a front wall extending upwardly and forwardly from one side ofsaid channel; a rear wall extending upwardly the other side of saidchannel, thence forwardly over said channel, so that both said frontwall and said rear wall terminate above and on the same side of saidchannel, said walls enclosing a tank, said front xover and spaced fromsaid inclined front wall,

said baffle board being hingedly supported so that it may be inclined ifdesired.

7. A flotation machine comprising: a tank; an air channel in the bottomof said tank; a perforated plate covering said channel; a front wall insaid tank extending forwardly and upwardly from the forward side of saidchannel and terminating in an overflow lip; a rear wall in said tankextending upwardly and forwardly from the rear side of said channel; anda baille board positioned above said plate and inclined to direct risingmaterial toward said rear wall.

. RANDALL?. AmNs. 00

